Absorbent materials in granular form are used for a variety of industrial and household purposes. Typical uses include the absorption of oil, grease and chemicals on floors and elsewhere, in animal toilet applications as a cat box absorbent, as carriers for chemicals, such as, pesticides and herbicides, in various agricultural and horticultural application, and as ground cover.
Such materials have heretofore almost exclusively consisted of absorbent clay granules, such as Fullers earth, although more recently it has been suggested in U.S. Pat. No. 4,163,674 to utilize gypsum, in the form of Plaster of Paris, as a base for granular absorbent materials. The product is formed in this prior art patent by forming a paste or slurry of the gypsum, which may also contain additives, such as finely divided paper, setting and hardening, and then grinding and crushing the dried material to granular form.
The granular product produced by this procedure consists mainly of gypsum and may contain only up to 20% by weight of the gypsum of other additives. The formation of a paste or slurry of the gypsum is essential in this prior art procedure, so that considerable energy is reguired to dry the product.